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arXiv · 1908.07427

New Spatially Resolved Imaging of the SR 21 Transition Disk and Constraints on the Small-Grain Disk Geometry

Steph Sallum·Andy Skemer·Josh Eisner·Nienke van der Marel·Patrick Sheehan·Laird Close·Mike Ireland·Jared Males·Katie Morzinski·Vanessa Bailey·Runa Briguglio·Alfio Puglisi
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Abstract

We present new 0.6 - 4 $\mu$m imaging of the SR 21 transition disk from Keck/NIRC2 and Magellan/MagAO. The protoplanetary disk around SR 21 has a large (~ 30 - 40 AU) clearing first inferred from its spectral energy distribution and later detected in sub-millimeter imaging. Both the gas and small dust grains are known to have a different morphology, with an inner truncation in CO at ~7 AU, and micron-sized dust detected within the millimeter clearing. Previous near-infrared imaging could not distinguish between an inner dust disk with a truncation at ~7 AU or one that extended to the sublimation radius. The imaging data presented here require an inner dust disk radius of a few AU, and complex structure such as a warp or spiral. We present a parametric warped disk model that can reproduce the observations. Reconciling the images with the spectral energy distribution gathered from the literature suggests grain growth to ~2 - 5 $\mu$m within the sub-millimeter clearing. The complex disk structure and possible grain growth can be connected to dynamical shaping by a giant-planet mass companion, a scenario supported by previous observational and theoretical studies.

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Steph Sallum, Andy Skemer, Josh Eisner, Nienke van der Marel, Patrick Sheehan, Laird Close, Mike Ireland, Jared Males, Katie Morzinski, Vanessa Bailey, Runa Briguglio, Alfio Puglisi. 2019-08-20. New Spatially Resolved Imaging of the SR 21 Transition Disk and Constraints on the Small-Grain Disk Geometry. https://doi.org/10.3847/1538-4357/ab3dae

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